1. Technical Field
This invention relates in general to remotely cooling a heat-generating component and in particular to a quick-release, hinge-like joint for a heat pipe in a notebook computer.
2. Background Art
Thermal management considerations pertinent to high performance notebook computer applications make it very desirable to use a heat pipe to cool a chip located in the base of the unit by transferring or dissipating heat to the large surface area that is available in the top cover. Since the top cover opens and closes relative to the base, there is a rotational hinge joint at the interface connecting the base to the cover that must be traversed by the cooling scheme.
A commonly employed cooling scheme utilizes one heat pipe in the cover and a second heat pipe in the base. The heat pipes are typically fragile, thin-walled cylinders which are sealed on each end and contain a vapor such as water. The heat pipes thermally communicate with one another via a hinge joint along the hinge axis. There are several prior art hinge joint designs currently in use. Each of these designs share a necessary common feature: they allow rotation of the cylindrical heat pipe within a bore or hollow sleeve. Until now, this limitation has required very tight tolerances and relatively elaborate fastening mechanisms to achieve the thermal hinge joint.
For effective heat transfer to take place at the joint, the cylindrical surface of the heat pipe must be in intimate communication within the bore of the hinge. That is, a minimum diametrical clearance, on the order of 25 micrometers or less, is required at the interface. In some cases, thermal grease is employed at the interface to obtain improved thermal conduction through the joint and to reduce friction between the two members. Unfortunately, even the use of thermal grease requires reasonably tight tolerances at the hinge. Thus, coupling tight tolerances with the fragile heat pipe has not substantially diminished the manufacturing and assembly difficulties of the thermal hinge. Moreover, none of these designs allow a quick assembly or disassembly of the components to the base and cover. Therefore, it is a feature of the present invention to overcome the difficulties of the prior art thermal hinges described by providing an improved heat pipe hinge joint.